The recording process for conventional DVD recorders may take 6 or more hours before the recording process is completed. During the recording process, typical DVD recorders (e.g., SONY RDR GX7, Philips DVR 890, 985, etc.) only write video, audio and/or navigation data to the disc. For normal recording, the DVD recorder receives audio/video from a tuner. The audio/video is encoded into an MPEG2 DVD format data stream and stored into memory. The DVD format data stream is recorded onto a DVD disc (e.g., a DVD+RW/+R disc). The encoding of DVD format data and the recording of DVD format data on the DVD disc are executed at the same time until recording is complete. When the DVD recorder stops recording, the DVD recorder will begin to generate a menu and write the navigation files and the file system to disc. The DVD disc can be played on a DVD player or on a personal computer (PC) after the navigation files and the file system is loaded to the DVD disc. If there is a system failure or a system crash while encoding DVD format data or recording the DVD format data to the DVD disc, the recorded data on the DVD disc cannot be viewed. Conventional DVD players do not write file systems and DVD navigation files to disc during system failure.
A system failure may occur when there is a power failure (e.g., a heavy voltage fluctuation, or the power is unplugged) or a system crash (e.g., the quality of DVD RW/R disc is low or a disc loader fails at high temperature). The next time the DVD recorder is turned on, the disc cannot be successfully read. The data recorded during the recording process will be lost and the disc will be seen by a player as an empty disc (DVD-RW) or a bad disc (DVD-R). To recover lost data, the consumer will have to take the disc to a technician in order to extract the data from the bad disc. It is difficult for consumers to retrieve lost data on discs without help from a technician.
It would be desirable to provide a method and/or apparatus to implement a safe recovery in DVD recordable/rewritable realtime recording in a manner suited for low cost, low power, and/or real time devices.